CVE-2025-9556

Langchaingo supports the use of jinja2 syntax when parsing prompts, which is in turn parsed using the gonja library v1.5.3. Gonja supports include and extends syntax to read files, which leads to a server side template injection vulnerability within langchaingo, allowing an attacker to insert a statement into a prompt to read the "etc/passwd" file.

CVSS 3.1

9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

0.7% chance of exploitation in the next 30 days; higher than 52% of CVEs (scores of 2026-10-25)

Published

2025-09-12

Modified

2026-10-19

Record from

the NVD, synced 2026-10-19

References

• https://github.com/tmc/langchaingo/pull/1348
• https://github.com/tmc/langchaingo/security/advisories/GHSA-mgcj-g55g-rf6h
• https://www.kb.cert.org/vuls/id/949137

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